Jetty structure



0d. 23, 19 45. 5 w LD 2,387,355

- JETTY STRUCTURE Filed June 27, 1942 2 Sheets-Sheet l ATTORNEY Oct. 23,1945. e. w. REHFELD JETTY STRUCTURE fi'iled June 27, 1942 ZShets -Sheet2 INVENTOR go/ye l Z/ Faye 0. M WM ATTORNEY Patented Oct. 23, 1945 4UNITED STATES PATENT OFFICE JETTY STRUCTURE George W. Rehfeld;Manhattan, Kans. Application June 27, 1942 Serial No. 448,813

Claims.

This invention relates to ,jetties for controlling banks of streams byretarding erosion and effecta It is well known that jetties of thischaracter aresubjected to bufieting forces tending to their destruction,particularly in times of high water when the current is swift andcarries large quantities of driftwood and the like. Consequently it hasbeen the practice to construct such jetties of structural metal membersas these members are of permanent character and when rigidlyconnectedtogether and laced provide the desired obstruction and withstand thebuifeting effects of driftwood while allowing free passage of the watertherethrough. However, structural members are relatively expensive anddifiicult to obtain, particularly within an economical distance from thesite of the .work. i i i U Therefore, the present invention contemplatesthe construction of jetties from less expensive and more readilyavailable materials such as concrete, the bulk of which, sand andgravel, is usually obtained at the site of the work, while the cementand reinforcing are available at nearby markets. However, concretejetties, when made sufliciently strong to withstand the shocks,buifetingand blows from driftage, are too heavy to be self-supporting and sinkinto the silt so that their effectiveness as an obstruction isrelatively short. i

It is, therefore, the purpose of the. present invention to provide aconcrete jetty of sufficiently light construction to be self-supportingupon the river. bed and which has the arm members thereof individuallyformed and flexibly connected to absorb the destructive blows andhammer-like shocks to which they maybe subjected.

Another object of the invention is to provide a jetty with a sufficientnumber of arms to be effective insupportingthe lacing and provide stablesupport on the river bed with sufiicient bearing to avoid sinkingthereof in quicksands and silt composing a 'river bottom.

structure, the preferred forms of which are illustrated in theaccompanying drawings, wherein:

Fig. 1 is a perspective view of a concrete jetty constructed inaccordance with the present invention.

Fig. 2 is a section through the jetty taken through those arms that arelocated with their axes in a common'plane.

Fig. 3 is a detail perspective view of the inner end of one of the armsparticularly illustrating the shape thereof whereby the arms when outerend of one of the arms.

Fig. 5 is a perspective view showing the initial step in the assembly ofthe jetty.

invention, I 'have provided improved details of Fig. 6 is a fragmentarysection similar to Fig. 2 showing a modified form of jetty structures.

Fig. '7 is a detail perspective view of the wire connecting member andone of the arms it connects in the form of the jetty illustrated in Fig.6.

Fig. 8 is a section similar to Fig. 2, taken through a further modifiedform of jetty.

Fig. 9 is a fragmentary perspective view of adjacent arms of the form ofthe jetty shown in Fig". 8, the arms being shown in disassembled spacedrelation.

Fig. 10 is a perspectiveview of a further modified form of flexibleconnection.

Referring more in detail to the drawings:

l designates a jetty such as used in controlling the bank of a streamand which has a plurality of individually formed arms 2, 3, 4, 5, 6 and1 arranged with inner ends thereof grouped together and the outer endsextending radially in the shape of a jack. Each arm is individuallyformed of concrete, preferably consisting of sand, water and cement,which may be mixed together near the job site to form a plastic masswhich is cast in a suitable mold, the molds being shaped to providerelatively narrow, elongated arms having side faces 8-9 and |0H, whichmay be arranged so that the opposite faces lie in parallel planes or thefaces may be tapered from the inner ends I 2 toward the outer ends I3 toincrease the strength thereof at the center of the jetty and reduce theweight of the outer ends of the arms correspondingly to the bendingforces acting along the length thereof. While I have illustrated thearms as being of. substantially rectangular cross-section, it is obviousthat they may be of other cross-sectional shapes.

The corners between the adjacent side faces are preferably bevelled, asat M, from a point spaced from the inner ends thereof to the outer endsto reduce the amount of material therein and yet maintain a highstrength to weight ratio. The

inner ends l of the arms converge from the respective faces, as at I6,and terminate in substantially rounded portions 11, as best shown inFig. 3. The inner ends of the arms are also provided with transverselyarranged openings 18 and i9, staggered withlrespect to each other andhave sufli cient taper to drain water therefrom and allow for expansionof ice toward the larger end in case of freezing temperatures, theopenings being to pass flexible ties 20 whereby the inner ends of thearms are drawntogether to form the cluster, as

, sufficient retardation to flow of water through the jetty: and causesinking of debris, silt and the like which builds up the surfaceon'whi'ch the jetty is supported. If desired, intermediate lacing may beprovided by equipping the arms with additional shown in Fig. 1. Theouter ends of the arms have similar transversely staggered openings 2 tand 22 which extend parallel with grooves 23 and 24 formed in the outerends of the arms, as best shown in Fig.4, The arms thus. shaped may beprovided with reinforcing, for example, ordinary rods. or wire,however,I find that lengths of flexible stranded cab1e 25. disposedlongitudinally and substantially coextensive with the axes of thearmsare more satisfactory and are preferable. The ends of the cables are.unraveled as shown at 25 and spread apart to betterreinforce theportions of the concrete surrounding the openings !8l9 and 2l22.

In assembling,,thefarms into a. jetty, three of them are'plac'ed to forma tripod, as. shown in Fig. 5', with the grooved or notched ends uponthe ground and with the inner ends brought together with the bevelledfacesv [5; of one arm resting against the adjacent bevelled faces. of anadjacent arm. The other three arms are then supported in a similar butinverted position with the converging faces, l6 resting upon thecorresponding faces'of the previously positioned arms. In this positionfour of the arms are located with their axes in a common plane and theother two arms. extend I at substantially right angles thereto. Whenthus positioned the faces l5 of those arms lying in a common plane form'socket-like recesses for. the other arms that extend at right anglesthereto whereby the arms are retained in centered relation] but. therounded surfaces allow for independent pivotal movement of therespective arms under shocks when the jetties are in use as laterdescribed. I

Prior to lacing, the arms may be. temporarily supported" in positionjbysuitable spacing rods, or by a jig having shape to retain the desiredangular relationship; Thei'nner ends of the. arms 2, 3,4 and 5 are tiedor laced together by passing a flexible, preferably stranded, cable 21through the openings I 9. of the respective arms, after which the endsofthe cable are-drawn together in lapped relation as shown at 28 in Fig...2. and. secured by a clamp 29.. A similar cable 30 is then passedthrough the openings l8 of the. arms 2, 1, 4 and 5 and the ends securedby a similar clamp, suificient tension having been drawn in therespective cables so that the ends of the arms are retained in abuttingcontact with each other as shown in Figs. '1 and 2.

The outer ends of the arms are then. connected by a lacing cable, forexample an end of a cable 3| islaid in the groove 23 of one of the armsand. then extended in reverse direction, through the. opening 2|, afterwhich the cable is again laid. in the groove 23 and extended to the neXtad-- j'acent arm where the cable is secured in like manner and thence tothe next arm, and. so. on until the place of starting, where'the endsare connectopenings such as illustrated at 32.

With the arms constructed and assembled as described, the jetties arerelatively light in weight and yet effectively withstand shocks to whichthey are subjected without breaking of the concrete as the respectiveends thereof are flexibly supported and one arm is. freeto moveindependently'of'the' other arms under, the blow :of a log or'thev likecarried in the stream.

"In placing the jetties they are preferably anchored in rows and. the.individual jetties are spaced apart by'cabl'es passingthrough crotchesformed between opposite arms" and secured. on the" respective/sidesthereof by fastening devices such as clamps, as in conventional jettyanchorage. The free ends of the'cables are anchored'to suitable dead menin the bank of the stream so that. the entire line of jetties is adaptedto position itself and thereby further resist shock that might tend toshatter the arms. The jetties when thus; anchored have three of thearms'supported' upon the bed'jofthe stream and the outer ends thereofbecome imbed'ded', while the other arms extend outwardly and upwardly"to provide the necessary obstruction in effecting a deposit of debris;silt andthe like carried in the water flowing through the jetties.

Attention is directed to the fact that should the arm of a jetty break,the flexible cables forming the reinforcing provide-a 'fiexibleanehorage toretain the broken sections together and allow for movementthereof without fracturingthe reinforcement Ye 'll'he'jetty showninFigs. 6 and 7 is substantially the same as that just d-escribed,'withthe exception of the flexible! connection for the inner ends'of'thearms. In this. arrangement the inner endsxof' the. armsare proyidedwith'axial bores. 33 to receive the; ends 3'4 of crossed. rods 3.5.thatare'securedtogether at their cross ing: points by welding or the like,as shown in Fig. 7.. In this construction the. arm's'are: assembled bysliding the inner ends thereof. onto the res-pective terminals. 34 of;the. rods. as shown in Fig.1 6. When the lacing is applied, as describedin the preferred form, the arms are retained uponthe terminals of theconnecting member. but the. connecting member provides sufficientmovement of the arms under force of a blow to absorb the shock whichwould ordinarily be destructive to the; concrete. p

In thev formof theinvention shown in Figs. ,8 and 9, the abutting arms38-3] and, 38- 39 are related in pairs, that is the flexible reinforcing40 extends through and forms the reinforcing of, an aligning arm Thereinforcing cable 4| of the arm. 42, however, extends through achannellike bore 43- of the. aligning arm 44, the bore starting withinthe axis of thearm 44 and emergin at a spaced. point. on the sidethereof so that after the connecting portion of the cable for the arms36 and 31 is crossed with that of the arms which are flexiblyinterconnected by the reinforcing to further enhance flexibility of thejetty.

Fig. shows a connection similar to that illustrated in Fig. 7, however,the pintles 45 are formed of separate pieces 48, 49 and 50, two ofwhich, 48 and 49, are bent at right angles and arranged oppositely toeach other so as to pass the third member 50 therebetween. The members,being linked together, provide for greater flexibility than the weldedform shown in Fig. '7.

From the foregoing it is obvious that I have provided a light weightjetty construction which is well adapted to be formed of concrete andwhich is capable of withstanding the shocks to which such jetties aresubjected.

What I claim and desire to secure by Letters Patent is:

The portion of the 1. A concrete jetty including, members arranged inconverging relation with ends thereof in abutting contact to form asubstantially tripod support, arm members having ends movably engagedwith the abutting ends of said support and diverging outwardly, meansretaining said ends in movable contact, and lacing connecting saidmembers.

2.A concrete jetty including, a plurality of radially extending arm-likemembers having bores in ends thereof, interconnected rod members havingterminals extending into said bores 5. A concrete jetty including, aplurality of radially extending arm-like members having bores in endsthereof, rod members interlinked with each other, a rod member extendingthrough the linked members, said rod members having terminals extendinginto said bores to retain said arm-like members in assembly, and lacingconnecting outer portions of said arm-like members.

6. A concrete jetty including, lower members arranged in convergingrelation with ends thereof in abutting contact to form a substantiallytripod support, upper arm members having ends engaged in abuttingcontact with the ends of,

the lower members of said support and diverging upwardly and outwardly,and cables connecting the abutting ends of said members to retain theshape of the jetty.

7. A jetty including a plurality of individually formed radiallyarranged arms extending outwardly from a common central point andupwardly and downwardly therefrom and having their inner ends in actualabutting relationship, means for flexibly connecting the inner abuttingends of the arms and maintaining the same in substantially abuttingrelationship and providing individual pivotal movement of the arms,

and means for connecting the outer ends of the arms with one another andcooperating with said flexible means to secure the arms in an uprightself sustaining structure.

8. A jetty including a plurality of individually formed radiallyarranged arms extending outwardly from a common central point andupwardly and downwardly therefrom and having their inner ends in actualabutting relationship,

ing arms, flexible reinforcing members in said arms and connecting thearms of said pairs, the

, connected ends of the arms of the respective and connecting the armsof said pairs, the connected ends of the arms of the respective pairsbeing spaced apart to provide movement therebetween, said pairs beingarranged with the connected ends of the arms in contact whereby one armis adapted to have slight rocking movement relative to the other arms,and lacing connecting said arms to maintain said arms in assembly, atleast one of said reinforcing members being loosely threaded through anopening in one of the arms and adapted to be attached to said arm afterassembly of the arms in said crossed relation.

said arms having openings in their inner abutting ends, flexible meansextending through said openings and connecting the inner abutting endsof the arms together and providing for individual pivotal movement ofthe arms, and means for connecting the outer ends of the arms with eachother and codperating with said flexible means to secure said arms in anupright self sustaining structure.

9. A jetty including a plurality of individually formed radiallyarranged arms extending upwardly and downwardly from a common centralpoint and having their inner ends in actual abutting relationship, andflexible means having at least two spaced apart connections with therespective arms for connecting the arms together forming an upright selfsustaining tetrahedron.

10. A jetty including a plurality of individually formed radiallyarranged arms extending upwardly and downwardly from a common centralpoint and having their inner ends arranged in actual abuttingrelationship, the downwardly extending arms providing a substantiallytripod support, and flexible means having at least two spaced apartconnections with the respective arms for flexibly connecting the armstogether forming an upright self sustaining structure and providing forlimited independent movement of said arms under shock.

GEORGE W. REHFELD.

